MECHANISM OF THE ANTIFRICTION ACTION OF MOLYBDENUM AND ZINC DITHIOPHOSPHATES AND DITHIOCARBAMATES

In a study of the antifriction properties of dialkyldithiophosphoric a nd dialkyldithiocarbamic complexes of molybdenum and zinc in a wide te mperature range (25-350 degrees C) it has been shown that molybdenum c ompounds are more effective than zinc complexes; in this case dithioca rbamic ligands ensure lower friction coefficients than dithiophosphori c ligands. Auger spectrometry has been used to study friction surfaces under load in the presence of lubricants with the addition of molybde num and zinc complexes. For all the compounds studied the distribution of chemical elements of additives over the depth of the surface layer s of the metal has been established. The layer of so-called secondary structures has the determining influence on the antifriction propertie s. A proportional relationship has been found between the thickness of this layer and the friction coefficient for complexes of different na ture. (C) 1998 Elsevier Science Ltd. All rights reserved.